name: fastlane description: Comprehensive guide to Fastlane automation for iOS and Android app deployment. Use when helping with mobile app releases, code signing, screenshots, TestFlight, App Store Connect, Google Play Store, beta distribution, CI/CD pipelines, or any Fastlane actions/lanes. Covers gym, match, pilot, deliver, supply, snapshot, screengrab, and 100+ other actions.

Fastlane Deployment Skill

Fastlane automates iOS and Android app building, testing, and deployment. This skill provides action references, common workflows, and Fastfile patterns.

Quick Reference

Core Tools (Aliases)

Common Workflows

iOS TestFlight Deployment

lane :beta do
  app_store_connect_api_key(
    key_id: ENV["ASC_KEY_ID"],
    issuer_id: ENV["ASC_ISSUER_ID"],
    key_filepath: ENV["ASC_KEY_PATH"]
  )
  increment_build_number
  match(type: "appstore")
  build_app(scheme: "MyApp")
  upload_to_testflight
  slack(message: "Build uploaded to TestFlight!")
end

iOS App Store Release

lane :release do
  app_store_connect_api_key(...)
  capture_screenshots
  sync_code_signing(type: "appstore")
  build_app(scheme: "MyApp")
  upload_to_app_store(
    submit_for_review: true,
    automatic_release: true
  )
end

Android Play Store Deployment

lane :deploy do
  gradle(task: "clean assembleRelease")
  upload_to_play_store(
    track: "production",
    json_key: ENV["GOOGLE_PLAY_JSON_KEY"]
  )
end

Android Beta (Internal Testing)

lane :beta do
  gradle(task: "clean bundleRelease")
  upload_to_play_store(
    track: "internal",
    aab: "app/build/outputs/bundle/release/app-release.aab"
  )
end

Code Signing with Match

# Appfile
app_identifier("com.example.app")

# Matchfile
git_url("git@github.com:org/certificates.git")
storage_mode("git")
type("appstore")

# Usage in lane
lane :setup_signing do
  match(type: "development")  # Dev certs
  match(type: "appstore")     # Distribution certs
end

CI/CD Integration

GitHub Actions Environment

lane :ci_build do
  setup_ci  # Sets up keychain for CI
  match(type: "appstore", readonly: true)
  build_app(scheme: "MyApp")
end

Environment Variables

# App Store Connect API Key (recommended over password auth)
app_store_connect_api_key(
  key_id: ENV["ASC_KEY_ID"],
  issuer_id: ENV["ASC_ISSUER_ID"],
  key_content: ENV["ASC_KEY_CONTENT"],  # Base64 encoded .p8
  is_key_content_base64: true
)

# Google Play Service Account
upload_to_play_store(
  json_key_data: ENV["GOOGLE_PLAY_JSON_KEY"]
)

Detailed Action References

For complete action parameters and examples, see:

• Building: references/building.md - gym, gradle, xcodebuild, cocoapods
• Code Signing: references/code-signing.md - match, cert, sigh, notarize
• App Store: references/app-store.md - deliver, pilot, produce, precheck
• Google Play: references/google-play.md - supply, gradle actions
• Screenshots: references/screenshots.md - snapshot, screengrab, frameit
• Testing: references/testing.md - scan, slather, swiftlint
• Utilities: references/utilities.md - notifications, source control, misc

Essential Commands

# Initialize fastlane
fastlane init

# List all actions
fastlane actions

# Get action details
fastlane action [action_name]

# Run a lane
bundle exec fastlane [lane_name]

# Run with verbose output
bundle exec fastlane [lane_name] --verbose

App Store Connect Restrictions

Metadata Character Limits

Screenshot Size Requirements

Known Issue: Screenshots from Xcode 26 beta simulators (iPhone 17 series) may have resolutions not yet recognized by App Store Connect. Use iPhone 16 series simulators.

API Key Configuration

The App Store Connect API key must be properly formatted in JSON:

{
  "key_id": "YOUR_KEY_ID",
  "issuer_id": "YOUR_ISSUER_ID",
  "key": "-----BEGIN PRIVATE KEY-----\nLINE1...\nLINE2...\n-----END PRIVATE KEY-----",
  "duration": 1200,
  "in_house": false
}

Critical: The PEM key MUST have \n newline characters between lines. A single-line PEM causes OpenSSL::PKey::ECError: invalid curve name.

Common Errors and Solutions

Fastfile Structure

# fastlane/Fastfile
default_platform(:ios)

platform :ios do
  before_all do
    # Runs before every lane
  end

  lane :test do
    run_tests(scheme: "MyApp")
  end

  lane :beta do
    # Beta deployment
  end

  after_all do |lane|
    # Runs after successful lane completion
  end

  error do |lane, exception|
    slack(
      message: "Error in #{lane}: #{exception.message}",
      success: false
    )
  end
end

platform :android do
  lane :deploy do
    gradle(task: "assembleRelease")
  end
end